Cup-shaped diamond grinding wheel



June 28, 1960 w. |NDB| AD 2,942,387

CUP-SHAPED DIAMOND GRINDING WHEEL Filed March 3, 1958 INVENTOR l4azozmck w. Lmoauo {33; I W I (3 V 7 ATTY.

States Patented June 28, 1960 Frederick W. Lindblad, Chicago, III. (835Illinois A've., Aurora, Ill.)

Filed Mar. 3, 1958, Ser. No. 718,736

Claims. (Cl. 51209) This invention relates to abrasive grinding wheels,par- .ticularly such grinding wheels as utilize diamond abrasivematerial. It is especially concerned with grinding wheels of the flaredcup type, that is one wherein an abrading section is combined witha bodysection that is of the shape of a flared cup.

It is one of the objects of the present invention to provide an abradingwheelof the above mentioned type which can be fabricated by combining aone piece prefabricated abrading section with a one piece prefabricatedbody section.

It is another object of the present invention to provide a flared cuptype'of abrading wheel wherein the grinding section and the core sectionmay each be prefabricated separately and then combined to form afinished wheel.

In a flared cup type grinding wheel wherein the ring of grindingmaterial is on the outside of the cup there are certain disadvantagesinsofar as concerns the holding of the grinding ring on the core. It isan object of the present invention to overcome many of these objectionsby locating the diamond ring on the inner side of the cup shaped coreand thereby utilizingthe sloping walls of the core to help hold thediamond ring in place, and

wherein the bond between the diamond core and the ring is undercompression when the Wheel is in use rather than under tension, therebyproducing a better holding action.

The attainment of the above and further objects of the present inventionwill be apparent from the following specifications taken in conjunctionwith the accompanying drawing forming a part thereof. :In the drawing:

Fig. 1 is a top plan view of the abrading'wheel embodying the presentinvention;

Fig. 2 is a side view of the wheel of Figure 1, in quarter.

section; a

Fig. 3 is a plan view illustrating modified construbtion; and

Fig. 4 is a sectional view taken along 44 of Fig. 3. Reference may nowbe had more particularly to the. drawing wherein like reference numeralsdesignate like parts throughout. 7

The wheel A of Figures 1 and 2 consists of a body or core 1 of agenerally frusto-conical shape having a diamond abrasive ring 2 imbeddedtherein. The body or core 1 has the usual opening 3 for mounting thesame upon the arbor of a machine. The edge 4 of the grinding ring 2 isthe working edge. The body 1 is a preformed flared cup shape body thatmay be moulded of any desired material, preferably plastic material, but

not limited to plastic material. A preferred plastic composition is ofnylon which imparts a desired small amount of resiliency to the core.Other suitable plastics that may also impart a limited amount ofresiliency to the core are tenite, etc.

2 8 terminates in a thin surface 10 that is concentric with the outerfrusto-conical surface of the core and which leaves a thin section 12 ofcore material at an obtuse angle to the shoulder 8. The inner surface 10may be' machined to the desired dimension if the dimension of the flaredcup as moulded is not precisely accurate.

The abrasive ring 2 is moulded to the shape shown and consists ofindustrial diamond abrasive particles moulded within a body of plastic.The composition of the diamond abrading ring 2 including the diamondparticles and the plastic filler may be any preferred conventional type,for instance as described in my United States Patent 2,703,437, issuedMarch 8, 1955. When the abrasive ring 2 has been fabricated and the core1 has been fabricated the two are assembled as shown, with a suitablebonding agent or cement between them. The bonding face between thediamond sectionand the core, and thatto check measure the diamondsection before assembly with thecore since the diamond section ispreformed accurately to shape before it is assembled with the preformedcore. It is easier to dress this type of wheel, and in addition there isa visual guide to help the operator determine when to redress the coreaway from the outside edge thereof. The highly objectionableconsequences of failure to dress the core are therefore minimized. Thesupport for the diamond section is along the entire interentireinterface is in compression when grinding pressure is applied to or bythe grinding ring 2. This better support gives longer life to thewheel.The core material may be of the type which will soften and be pushedaway if the pressure is great enough. As a result there is no The core 1has a radially'extending seat for the ring 2,

danger of abusing the wheel even if the core material is not dressedaway.

Figures 3 and 4 show a grinding wheel 14 similar to that of Figures 1and 2 but dilfering therefrom in that the inner. surface of the flaredcup shaped core is provided with vanes 15 that act as fan blades andmaintain a stream of air in movement across the inner face of theabrasive ring 2 thus facilitating cooling of that ring If desired, watercooling may be used, in which event the vanes move the water outwardlytowards and across the inner surface of the abrasive ring 2. V

In compliance with requirements of the patent statutes I have hereinshown and described a preferred embodiment'of the present invention. Itis, however, to be understood that the invention is not limited to theconstruction herein shown, the same being merely illustrative of theprinciplesof the invention. What is considered new and to be covered byLetters Patentis;

l. A grinding wheel comprising a hollow frusto conicalsupporting bodyhaving means at the smaller diameter end for-mounting the same forrotation about the central longitudinal axis of the body, the largerdiameter end of the body having a radially extending seat for a grindingring, said seat comprising an annular shoulder formed on the innersurface of the supporting body and facing in the direction towards thelarger diameter end of the body and said shoulder extending fromthe'interior of the body towards the exterior thereof and at rightangles to the longitudinal axis of the body, anda" t. hollowfrustoconical grinding ring the small diameter of which rests on said seat andsaid ring flaring radially outwardly from said seat towards its largerdiameter end and said ring being surrounded and backed at its frustoconical surface to a major portion of the axial length of its frustoconical surface by the part of the supportingbodythat'extends from theseat to'the larger diameter end'of :the body, said ring being ofabradablermaterial teiminating at its larger diameter end in a grindingsurface that is substantially parallel to said grinding ring seat onthesaid body thering being of substantially smaller mass thanithe mass ofthe supporting body, and the portion of the supporting body between theseat and the outermost larger diameter end thereof being of plasticmaterial that may be progressively dressed away as the grinding surfaceof the grinding ring is progressively worn whereby the edge of thesupporting body at the larger diameter end thereof may be maintained inreinforcing position around the ring immediately adjacent to thegrinding surface thereof during the progressive wearing away of thering.

2. A grinding wheel comprising a hollow frusto conical supporting bodyhaving means at the smaller diametcrend for mounting the same forrotation about the central longitudinal axis of the body, the largerdiameter end of the-body having a radially extending seat fora grindingring, said seat comprising an annular shoulder fonned on the innersurface of the supporting body and facing in the direction towards thelarger diameter end of the body and extending from the interior of thebody towards the exterior thereof and making an obtuse angle with thefrusto-conical portion of the inner surface'ofthe body that extends fromthe shoulder towards the larger diameter-end of the body, and a hollowfrusto'conical grinding ring the smaller diameter of which rests on saidseat and said ring flaring radially outwardly from said seat towards itslarger diameter end and said ring being surrounded and backed at itsfrusto conical surface -to a major portion of the axial length of itsfrustoconical surface by the part of the supporting body that extendsfrom the seat to the larger diameter end of the body, said ringterminating at its larger diameter end in a grinding surface, the ringbeing of substantially smaller mass than the mass of the supportingbody, and the portion of the supporting body between the seat and theoutermost larger diameter end thereof being of plastic material that maybe progressively dressed 'away as the grinding surface of the grindingring is progressively'worn whereby the edge of the supporting body atthe larger diameter end thereof may be maintained in reinforcingposition around the ring immediately adjacent to the grinding surfacethereof during the progressive wearing away of the ring.

3. A grinding wheel such as defined in claim 1 having fluid circulatingvanes on the inner surface of the frusto conical supporting body formaintaining flow of cooling fluid within the body in movement radiallyoutwardly and over the inner frusto-conical surface of the abradingring.

4. A grinding wheel such as defined in claim 2 having fluid circulatingvanes on the inner surface of the frusto conical supporting body formaintaining a flow of cooling fluid within the body in movement radiallyoutwardly and over the inner frusto-conical surface of the abradingring.

5. A grinding wheel comprising a hollow frusto conical body having meansat the smaller diameter end for mounting the same, a frusto conicalgrinding ring'located on the inner surface of said body at the largerdiameter end thereof and backed by the frusto conical surface of thebody over a major portion thereof, and cooling vanes on the innersurface of said body for maintaining a flow of cooling fluid radiallyoutwardly and over the frusto-conical surface of the grinding ring. 7

6. An abrasive grinding wheel comprising a hollow frusto-conical bodyhaving means at its smaller diameter end for mounting the same, agrinding ring seat formed at the inner circumference of the largerdiameter end of .the body, and a frusto conical grinding ring resting onsaid seat and reenforced by being backed at its outer frusto-conicalsurface by said body to a major extent of the outer frusto-conicalsurface of said ring.

7.'An abrasive grinding wheel comprising a hollow frusto-conical bodyhaving means at its smaller diameter end for mounting the same, agrinding ring seat formed at the inner circumference-of the largerdiametenend of the body, and a frusto conical grinding ring resting onsaid seat and reenforced by being backed at its outer frusto-conicalsurface by said body to a major extent of the outer frusto-conicalsurface of said ring, said ring including a diamond abrasive and saidbody being of plastic so that as the ring is progressively worn away thebody may be progressively dressed away while maintaining itsreenforcement around the ring up to the region of the abrading workingsurface of the ring.

8. A grinding wheel of the type comprising a grinding ring ofcomparatively expensive material and a supporting body therefor ofmaterial that is inexpensive in com-' parison with the material ofthe'grinding wheel, said supporting body being of frusto conical shapeadapted to be mounted for rotation about the central longitudinal axisof the frusto cone, the larger diameter end of the frusto cone having aradially extending seat for a grinding ring; said seat comprising anannular shoulder formed on the inner surface of the supporting body andfacing in the direction towards the larger diameter end of the body andextending fromthe interior of the frusto cone towards the exteriorthereof, and a hollow frusto conical grinding ring the smaller diameterend of which rests on said seat and said'ring flaring radially outwardlyfrom said seat towards the larger diameter end of the ring and the ringbeing surrounded and backed at its frusto-conical surface over a majorportion thereof by the part of the supporting body that extends from theseat to the larger diameter end thereof, the'ring being of substantiallysmaller mass that the mass of the supporting body.

9. A grinding wheel comprising a hollow frusto-conical body having meansat the smaller diameter for mounting same, a frusto-conical grindingring of abradable material and being located on the inner surface ofsaid body at the larger diameter end thereof, said ring being backed bythe frusto-conical surface of the body over a major portion of thefrusto-conical surface of the ring, the frusto-conical body being of aplastic material that may be progressively dressed away as the grindingsurface of the ring is progressively worn, and cooling vanes on theinner surface of said body for maintaining a flow of cooling fluidradially outwardly and over the frusto-conical surface of the grindingring.

10. A grinding wheel comprising a hollow body having the outerfrusto-conical surface of said ring being backed by the part of the bodyhaving the frusto-conical surface and said part of the body extendingover a major portion of the outer frusto-conical surface of the ring toreinforce the ring up to the region of the working surface thereof.

References Cited in the file of this patent UNITED STATES PATENTS2,307,312 Whiting Ian. 5, 1943 2,320,130 Harris May 25, 1943 2,806,331Hoye Sept. 17, 1957

